Oil tank for a rotary piston internal combustion engine with dry-sump lubrication

ABSTRACT

An oil tank for a rotary piston internal combustion engine, especially of trochoidal type of construction, with a dry sump lubrication for the drive unit and with a metered fresh oil lubrication for the piston cam surface in the housing casing; the oil tank for the dry sump lubrication includes inlet, outlet, venting and filler connections whereby a second tank for the fresh oil lubrication is arranged on the inside of the oil tank at a place substantially directly below the filler inlet and is in communication with the oil tank by way of an overflow while having its own outlet.

Utte States atent H51 3,638,760 Lamm 1 Feb. 1, 1972 [54] OIL TANK FOR A ROTARY PISTON 3,528,226 9/1970 Everett ..55/277 INTERNAL COMBUSTION ENGINE 3,523,592 8/1970 Fenton ..l23/l96 X Huber i [72] Inventor: Heinz Lamm, Esslingen-St. Bernhardt, FOREIGN PATENTS 0R APPLICATIONS Germany 931,735 7/1963 Great Britain 184/623 Assignee: Baimler.8mz Stuttgart- France i Unterturkheim. Gennany [2 Filed: Mar. 3 1970 Primary Examiner-Manuel A. Antonakm Attorney-Craig, Antonelli and Hill [21] Appl.No.: 24,279

[57] ABSTRACT [30] Foreign Application Priority Data An oil tank for a rotary piston internal combustion engine, especially of trochoidal type of construction, with a dry sump 1969 Germany 19 16 967'6 lubrication for the drive unit and with a metered fresh oil lubrication for the piston cam surface in the housing casing; [52] US. Cl. ..184/6.23, 55/277, 1231/81 the oil tank for the y p lubrication indudes inlet outlet, [51] Int. CL F16 39/00 venting and filler connections whereby a second tank for the [581 new ii'IIIIIIIIfIIf.'..'.'.'..'.'.'If.'iii/5H"5'50,571 576- freshenlubricationisamgedomheinsidwftheoflmkat 134/523 10 17 1 123/195 55/159 a place substantially directly below the filler inlet and is in 2 communication with the oil tank by way of an overflow while having its own outlet. [56] References Cited 18 Claims, 2 Drawing Figures UNITED STATES PATENTS 3,207,203 9/1965 Mack... ..137/574 X 7 20 Z l 2 I 11 m i I; I I |5 1;

/ l z I E H1 1 n1 mama) FEB 1 1972 3638.760

INVENTOR HEINZ LAMM W Mull/1 ATTORNHS OIL TANK FOR A ROTARY PISTON INTERNAL COMBUSTION ENGINE WITH DRY-SUM? LUBRICATION The present invention relates to an oil tank for a rotary piston internal combustion engine of especially trochoidal construction with a dry-sump lubrication of the drive unit and with a metered fresh oil lubrication of the piston contact or running surface in the casing of the housing, which includes an inlet and outlet line, a vent line, and a filler inlet.

If a dry-sump lubrication is provided in a rotary piston internal combustion engine, the arrangement of an oil tank separate from the internal combustion engine is necessary. If therebeyond a lubrication of the piston cam surface with fresh oil, free of air and gasoline, is to be additionally undertaken, a second container becomes necessary.

The present invention aims at reducing the expenditures to be made with an arrangement of a dry-sump lubrication and additionally of a fresh oil lubrication. The underlying problems are solved according to the present invention in that a second container receiving the oil supply for the fresh oil lubrication is arranged directly below the filler pipe in the oil container or tank receiving the oil supply for the lubricating oil circulation system of the drive unit, which second tank is connected with the oil tank by way of an overflow and has a separate discharge or outlet.

In addition to the reduction of the structural expenditures, that is achieved by the combination of the oil supply tanks, additionally further functional advantages are achieved by the present invention. As a result of the arrangement of the tank for the fresh oil lubrication directly below the filler inlet of the oil tank, there always takes place with certainty a filling of the tank for the fresh oil lubrication. Only when this tank is full, the oil flows into the oil tank for the dry-sump lubrication by way of the overflow. Furthermore, a warming-up of the oil for the fresh oil lubrication is brought about in an advantageous manner by the oil for the lubrication of the drive unit which carries out a circulation. This warming-up can be further enhanced in particular in that according to a further feature of the present invention the second tank is in connection with the oil supply in the oil tank by way of a large surface.

In order that gasoline taken along far-reachingly by the oil flowing back from the drive unit into the oil tank is removed, an inclined runoff wall may be provided above the level of the oil supply below the feedline or inlet line of the oil participating in the lubricating circulatory system, which runoff wall extends transversely through the oil tank and terminates closely in front of the second tank, if possible with a sharp edge.

The oil flowing back into the oil tank flows off along this runoff wall in a thin film so that the gas bubbles may be readily broken up and released. Especially this release occurs at the edge of the runoff wall, over which flows the oil into the tank.

In order that the spray oil does not reach the venting line, which is appropriately connected to the suction system of the internal combustion engine, the present invention provides a preferably trapezoidally shaped protecting wall above the feedline or inlet and below the venting line, whose end is disposed relatively close above the runoff wall. Oil arriving by way of the inlet is deflected by this protecting wall toward the runoff wall. Gases freed from the oil flow about this protecting wall toward the venting line.

According to a further development and feature of the present invention, the oil tank may consist of a transparent, synthetic resinous material and may be provided thereat with markings for the permissive minimum level of the oil participating in the lubricating circulation and the oil for the fresh oil lubrication.

Accordingly, it is an object of the present invention to provide an oil tank structure for a rotary piston internal combustion engine with dry-sump lubrication which avoids by simple means the aforementioned shortcomings and drawbacks encountered in the prior art.

Another object of the present invention resides in an oil tank structure for a rotary piston internal combustion engine of the type described above which is simple in construction, obviates the need for two separate tanks and generally reduces the structural expenditures connected therewith.

A further object of the present invention resides in an oil tank structure for a rotary piston internal combustion engine with dry-sump lubrication and fresh oil lubrication for the piston contact or running surface in the housing casing which assures an adequate supply of oil for the fresh oil lubrication, provides a preheating of the oil for the fresh oil lubrication and effectively removes air bubbles and gasoline from the oil returning to the oil tank.

These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

FIG. I is a longitudinal cross-sectional view through an oil tank structure in accordance with the present invention; and

FIG. 2 is a cross-sectional view through the oil tank structure taken along line IIII of FIG. 1.

Referring now to the drawing wherein like reference numerals are used throughout the two views to designate like parts, reference numeral 1 generally designates therein the oil tank which has a square shape and is made from a transparent synthetic resinous material of any known, suitable type. The tank generally designated by reference numeral 3 which is open at the top, is arranged in the oil tank I at the wall 2 thereof; the tank 3 is in operative connection by means of its three sidewalls 4, 5 and 6 with the space 7 for the oil supply of the dry-sump lubrication. The space 8 in the tank 3 serves for storing the oil supply for the fresh oil lubrication. The filler pipe 10 is arranged above the tank 3 in the upper closure wall 9 of the oil tank 1. Both the space 7 as also the space 8 are provided at the bottom wall 11 with connecting pipes for the outlets 12 and 13, respectively. The discharge or outlet line 12 leads to a pressure pump which supplies the lubricating system of the drive unit of the internal combustion engine. The discharge or outlet line 13 is connected with a metering pump, by means of which fresh oil is conducted from the space 8 in metered quantities to the piston running surface (not shown) in the housing and to the sealing elements of the internal combustion engine.

The runoff wall 16 is arranged at the wall I5 of the oil tank 1 above the level 14 of the oil intended for the lubricating circulatory system which is present in the space 7; the runoff wall 16 extends to the walls 17 and 18 of the oil tank 1 and is inclined downwardly from the wall 15 and terminates in front of the tank 3. The inlet 19 is arranged in the wall 15 closely above the runoff wall 16. The trapezoidally shaped protecting wall 20 is disposed above the inlet 19; the protective wall 20 is shorter than the runoff wall 16 but is constructed more strongly inclined than the latter. Furthermore, the venting line 21 is disposed in the upper wall 9 of the oil tank above the protective wall 20.

During filling-in of oil into the oil tank 1, at first the tank 3 is filled by reason of the direct location of the inlet or filler pipe 10 above the tank 3. That quantity of oil which the tank 3 cannot accommodate, runs over into the space 7 by way of the overflow 22. Whereas the oil in the space 8 of the tank 3 only serves for the fresh oil lubrication of the piston running surface, i.e., does not participate in a circulatory system, the oil in the space 7 carries out a circulation in a conventional manner. The oil flowing back into the space 7 out of the circulatory system runs along the runoff wall I6 in a thin layer and flows off by way of the free edge of this wall in the downward direction. It thereby frees itself of any gas. This gas flows about the protecting wall 20 and enters into the vent line 21. The protecting wall 20 prevents effectively that oil leaving the line 19 in the form of splashes or sprays could reach the area of the vent line 21. Additionally, the protecting wall 20 conducts the oil in the direction toward the runoff wall 16.

The space 7 is at least twice as large as the space 8 whereby the space 8 is to have approximately a capacity of about 2 to about 4 liters of oil.

Since the oil tank is made from a transparent material, an oil-measuring stick may be dispensed with. Appropriate markings at the oil tank itself suffice for that purpose. Possibly, the oil tank may also have a configuration, different from the illustrated shape, which is adapted to the accommodation conditions.

While I have shown and described only one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art, and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

I claim:

1. An oil tank structure for a rotary piston internal combustion engine which includes a housing with a casing forming a piston contact surface, a rotating piston in said housing, a dry-sump lubrication means for the drive unit of the internal combustion engine, a metered fresh oil lubrication means of the piston contact surface in the casing, and inlet, outlet venting and filler means for said oil tank structure, characterized by a first oil tank providing an oil supply for the lubrication means of the drive unit, and a second tank providing an oil supply of the fresh oil lubrication means arranged in the oil tank receiving the oil supply for the lubricating means of the drive unit, substantially directly below the filler means, said second tank being operatively connected with the first oil tank by way of overflow means and having a separate outlet means.

2. An oil tank structure according to claim 1, characterized in that the second tank is operatively connected with the oil supply in the first oil tank by way of a large surface.

3. An oil tank structure according to claim 2, characterized in that a runoff wall means is provided above the level of the oil supply below the inlet means of the oil in said first tank and in that said runoff wall means extends transversely through the oil tank.

4. An oil tank structure according to claim 3, characterized in that the runoff wall means terminates closely in front of the second tank.

5. An oil tank structure according to claim 4, characterized in that the runoff wall means terminates closely in front of the second tank with a sharp edge.

6. An oil tank structure according to claim 3, characterized in that a protective wall means is arranged above the inlet means and below the vent means, the end of said protective wall means being disposed relatively close above'the runoff wall means.

7. An oil tank structure according to claim 6, characterized in that said protective wall means is of substantially trapezoidal shape.

8. An oil tank structure according to claim 7, characterized in that the oil tank structure consists of substantially transparent synthetic resinous material provided with markings for the permissive minimum level of the oil in said first tank and of the oil for the fresh oil lubrication means in said second tank.

9. An oil tank structure according to claim 8, characterized in that the runoff wall means terminates closely in front of the second tank.

10. An oil tank structure according to claim 9, characterized in that the runoff wall means terminates closely in front of the second tank with a sharp edge.

1 1. An oil tank structure according to claim 10, characterized in that the dry-sump lubrication means is connected by way of its outlet means with the drive unit of a rotary piston internal combustion engine of trochoidal construction while the fresh oil lubrication means is connected with the contact surface in the casing of the engine housing by way of a metering m ll. An oil tank structure according to claim 1, characterized in that a runoff wall means is provided above the level of the oil supply below the inlet means of the oil in said first tank, and in that said runoff wall means extends transversely through the oil tank.

13. An oil tank structure according to claim 12, characterized in that the runoff wall means terminates closely in front of the second tank.

14. An oil tank structure according to claim 13, characterized in that the runoff wall means terminates closely in front of the second tank with a sharp edge.

15. An oil tank structure according to claim 13, characterized in that a protective wall means is arranged above the inlet means and below the vent means, the end of said protective wail means being disposed relatively close above the runoff wall means.

16. An oil tank structure according to claim l5, characterized in that said protective wall means is of substantially trapezoidal shape.

17. An oil tank structure according to claim I, characterized in that the oil tank structure consists of substantially transparent synthetic resinous material provided with markings for the permissive minimum level of the oil in said first tank and of the oil for the fresh oil lubrication means in the second tank.

18. An oil tank structure according to claim 1, characterized in that the dry-sump lubrication means is connected by way of its outlet means with the drive unit of a rotary piston internal combustion engine of trochoidal construction while the fresh oil lubrication means is connected with the contact surface in the casing of the engine housing by way of a metering pump.

UNITED STATES PATENT OFFICE CERTIFICATE OF CDRRECTION Patent No. 3,638,760 Dated February 1, 1972 Inventor(s) Heinz Larnm It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Title Page, left column, line 6, which now reads:

"Assignee: Baimler-Benz Aktiengesellschaft, Stuttgartshould read as follows:

Assignee: Daimler-Ben z Aktie-ngesellschaft, Stuttgart- Signed and sealed this 15th day of August 1972.

(SEAL) Attest:

EDWARD M.FLETGHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents )RM PO-IOSO (10-69) USCOMM-DC 60376-P69 fi uls. GOVERNMENT PRINTING oFncE 1959 0-366-31 

1. An oil tank structure for a rotary piston internal combustion engine which includes a housing with a casing forming a piston contact surface, a rotating piston in said housing, a dry-sump lubrication means for the drive unit of the internal combustion engine, a metered fresh oil lubrication means of the piston contact surface in the casing, and inlet, outlet venting and filler means for said oil tank structure, characterized by a first oil tank providing an oil supply for the lubrication means of the drive unit, and a second tank providing an oil supply of the fresh oil lubrication means arranged in the oil tank receiving the oil supply for the lubricating means of the drive unit, substantially directly below the filler means, said second tank being operatively connected with the first oil tank by way of overflow means and having a separate outlet means.
 2. An oil tank structure according to claim 1, characterized in that the second tank is operatively connected with the oil supply in the first oil tank by way of a large surface.
 3. An oil tank structure according to claim 2, characterized in that a runoff wall means is provided above the level of the oil supply below the inlet means of the oil in said first tank and in that said runoff wall means extends transversely through the oil tank.
 4. AN oil tank structure according to claim 3, characterized in that the runoff wall means terminates closely in front of the second tank.
 5. An oil tank structure according to claim 4, characterized in that the runoff wall means terminates closely in front of the second tank with a sharp edge.
 6. An oil tank structure according to claim 3, characterized in that a protective wall means is arranged above the inlet means and below the vent means, the end of said protective wall means being disposed relatively close above the runoff wall means.
 7. An oil tank structure according to claim 6, characterized in that said protective wall means is of substantially trapezoidal shape.
 8. An oil tank structure according to claim 7, characterized in that the oil tank structure consists of substantially transparent synthetic resinous material provided with markings for the permissive minimum level of the oil in said first tank and of the oil for the fresh oil lubrication means in said second tank.
 9. An oil tank structure according to claim 8, characterized in that the runoff wall means terminates closely in front of the second tank.
 10. An oil tank structure according to claim 9, characterized in that the runoff wall means terminates closely in front of the second tank with a sharp edge.
 11. An oil tank structure according to claim 10, characterized in that the dry-sump lubrication means is connected by way of its outlet means with the drive unit of a rotary piston internal combustion engine of trochoidal construction while the fresh oil lubrication means is connected with the contact surface in the casing of the engine housing by way of a metering pump.
 12. An oil tank structure according to claim 1, characterized in that a runoff wall means is provided above the level of the oil supply below the inlet means of the oil in said first tank, and in that said runoff wall means extends transversely through the oil tank.
 13. An oil tank structure according to claim 12, characterized in that the runoff wall means terminates closely in front of the second tank.
 14. An oil tank structure according to claim 13, characterized in that the runoff wall means terminates closely in front of the second tank with a sharp edge.
 15. An oil tank structure according to claim 13, characterized in that a protective wall means is arranged above the inlet means and below the vent means, the end of said protective wall means being disposed relatively close above the runoff wall means.
 16. An oil tank structure according to claim 15, characterized in that said protective wall means is of substantially trapezoidal shape.
 17. An oil tank structure according to claim 1, characterized in that the oil tank structure consists of substantially transparent synthetic resinous material provided with markings for the permissive minimum level of the oil in said first tank and of the oil for the fresh oil lubrication means in the second tank.
 18. An oil tank structure according to claim 1, characterized in that the dry-sump lubrication means is connected by way of its outlet means with the drive unit of a rotary piston internal combustion engine of trochoidal construction while the fresh oil lubrication means is connected with the contact surface in the casing of the engine housing by way of a metering pump. 